function expand_collapse(index) {
	var sub = document.getElementById('ul_' + index);
	var main = document.getElementById('dt_' + index);  
	var str = main.innerHTML;
	var index = str.indexOf('[-]', 0);
	
	if (index != -1) {
		main.innerHTML = str.replace('[-]','[+]');		
		sub.style.display = 'none';
	} else {
		main.innerHTML = str.replace('[+]','[-]');
		sub.style.display = '';		
	}
}
